diff --git a/ChangeLog.md b/ChangeLog.md
index e5389886..7025d519 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -82,6 +82,16 @@ JPEG images.  This was known to cause a buffer overflow when attempting to
 decompress some such images using `tjDecompressToYUV2()` or
 `tjDecompressToYUVPlanes()`.
 
+11. Fixed an issue, detected by ASan, whereby attempting to losslessly
+transform a specially-crafted malformed JPEG image containing an
+extremely-high-frequency coefficient block (junk image data that could never be
+generated by a legitimate JPEG compressor) could cause the Huffman encoder's
+local buffer to be overrun. (Refer to 1.4.0[9] and 1.4beta1[15].)  Given that
+the buffer overrun was fully contained within the stack and did not cause a
+segfault or other user-visible errant behavior, and given that the lossless
+transformer (unlike the decompressor) is not generally exposed to arbitrary
+data exploits, this issue did not likely pose a security risk.
+
 
 2.0.3
 =====
diff --git a/jchuff.c b/jchuff.c
index 8fd7a8bf..18cc91f3 100644
--- a/jchuff.c
+++ b/jchuff.c
@@ -453,7 +453,7 @@ dump_buffer(working_state *state)
  * scanning order-- 1, 8, 16, etc.), then this will produce an encoded block
  * larger than 200 bytes.
  */
-#define BUFSIZE  (DCTSIZE2 * 4)
+#define BUFSIZE  (DCTSIZE2 * 8)
 
 #define LOAD_BUFFER() { \
   if (state->free_in_buffer < BUFSIZE) { \